[PATCH v2 2/2] Enable support for x86 debug registers on NetBSD.

John Baldwin
2017-07-25T16:51:32Z

NetBSD recently added PT_GETDBREGS and PT_SETDBREGS ptrace operations
that match the existing ones supported by x86-bsd-nat.c. NetBSD's
headers do not provide the DBREG_DRX helper macro, so define a local
version in x86-bsd-nat.c. In addition, add the x86-nat.o and x86-dregs.o
object files to the native NetBSD x86 build targets.

gdb/ChangeLog:

* configure.nat: Add "x86-nat.o x86-dregs.o" for NetBSD/amd64 and
NetBSD/i386.
* x86-bsd-nat.c [!DBREG_DRX && __NetBSD__]: Define DBREG_DRX.
---
gdb/ChangeLog | 6 ++++++
gdb/configure.nat | 8 ++++----
gdb/x86-bsd-nat.c | 9 +++++++--
3 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index e06712d645..e24698ae30 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,11 @@
2017-07-25 John Baldwin <jhb@FreeBSD.org>

+ * configure.nat: Add "x86-nat.o x86-dregs.o" for NetBSD/amd64 and
+ NetBSD/i386.
+ * x86-bsd-nat.c [!DBREG_DRX && __NetBSD__]: Define DBREG_DRX.
+
+2017-07-25 John Baldwin <jhb@FreeBSD.org>
+
* bsd-kvm.o: Define _KMEMUSER.
* configure.ac: Define _KMEMUSER when checking for "struct lwp".
* configure: Regenerate.
diff --git a/gdb/configure.nat b/gdb/configure.nat
index b32c9aa849..b1dda30852 100644
--- a/gdb/configure.nat
+++ b/gdb/configure.nat
@@ -338,8 +338,8 @@ case ${gdb_host} in
case ${gdb_host_cpu} in
i386)
# Host: NetBSD/amd64
- NATDEPFILES="${NATDEPFILES} nbsd-nat.o amd64-nat.o \
- x86-bsd-nat.o amd64-bsd-nat.o amd64-nbsd-nat.o"
+ NATDEPFILES="${NATDEPFILES} nbsd-nat.o amd64-nat.o x86-nat.o \
+ x86-dregs.o x86-bsd-nat.o amd64-bsd-nat.o amd64-nbsd-nat.o"
;;
sparc)
# Host: NetBSD/sparc64
@@ -358,8 +358,8 @@ case ${gdb_host} in
;;
i386)
# Host: NetBSD/i386 ELF
- NATDEPFILES="${NATDEPFILES} nbsd-nat.o x86-bsd-nat.o \
- i386-bsd-nat.o i386-nbsd-nat.o bsd-kvm.o"
+ NATDEPFILES="${NATDEPFILES} nbsd-nat.o x86-nat.o x86-dregs.o \
+ x86-bsd-nat.o i386-bsd-nat.o i386-nbsd-nat.o bsd-kvm.o"
LOADLIBES='-lkvm'
;;
m68k)
diff --git a/gdb/x86-bsd-nat.c b/gdb/x86-bsd-nat.c
index 2ff661c179..1d37b2f05d 100644
--- a/gdb/x86-bsd-nat.c
+++ b/gdb/x86-bsd-nat.c
@@ -51,11 +51,16 @@ x86bsd_mourn_inferior (struct target_ops *ops)
super_mourn_inferior (ops);
}

-/* Not all versions of FreeBSD/i386 that support the debug registers
- have this macro. */
+/* Helper macro to access debug register X. FreeBSD/amd64 and modern
+ versions of FreeBSD/i386 provide this macro in system headers. Define
+ a local version for systems that do not provide it. */
#ifndef DBREG_DRX
+#ifdef __NetBSD__
+#define DBREG_DRX(d, x) ((d)->dr[x])
+#else
#define DBREG_DRX(d, x) ((&d->dr0)[x])
#endif
+#endif

static unsigned long
x86bsd_dr_get (ptid_t ptid, int regnum)
--
2.13.3